Footemineite
A valid IMA mineral species
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About Footemineite
One more view of the quarry in May, 1968
Foote Lithium Co. Mine, Kings Mountain, Cleveland County, North Carolina, USA
Foote Lithium Co. Mine, Kings Mountain, Cleveland County, North Carolina, USA
Formula:
Ca2Mn2+Mn2+2Mn2+2Be4(PO4)6(OH)4 · 6H2O
Colour:
Yellow
Lustre:
Vitreous, Pearly
Hardness:
4½ - 5
Specific Gravity:
2.873 (Calculated)
Crystal System:
Triclinic
Member of:
Name:
Named for the type locality, Foote Mine, North Carolina, USA.
Dimorph of:
Isostructural with:
Unique Identifiers
Mindat ID:
30765
Long-form identifier:
mindat:1:1:30765:3
IMA Classification of Footemineite
Classification of Footemineite
8.DA.10
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
A : With small (and occasionally larger) cations
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
A : With small (and occasionally larger) cations
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ftm | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Footemineite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Footemineite
Vitreous, Pearly
Transparency:
Transparent
Colour:
Yellow
Streak:
White
Hardness:
4½ - 5 on Mohs scale
Comment:
By analogy with other roscherite-group minerals.
Tenacity:
Brittle
Cleavage:
Distinct/Good
Good on {011} and {100}
Good on {011} and {100}
Density:
2.873 g/cm3 (Calculated)
Optical Data of Footemineite
Type:
Biaxial (-)
RI values:
nα = 01.620(2) nβ = 01.627(2) nγ = 1.634(2)
2V:
Measured: 080° , Calculated: 089.6°
Max. Birefringence:
δ = 0.014
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
weak r > v or r < v
Pleochroism:
Visible
Comments:
β (brownish yellow) > α = γ (yellow).
Chemistry of Footemineite
Mindat Formula:
Ca2Mn2+Mn2+2Mn2+2Be4(PO4)6(OH)4 · 6H2O
Element Weights:
Crystallography of Footemineite
Crystal System:
Triclinic
Class (H-M):
1 - Pedial
Space Group:
P1
Cell Parameters:
a = 6.742 Å, b = 9.883 Å, c = 9.981 Å
α = 74.12°, β = 86.1°, γ = 87.36°
α = 74.12°, β = 86.1°, γ = 87.36°
Ratio:
a:b:c = 0.682 : 1 : 1.01
Unit Cell V:
637.92 ų (Calculated from Unit Cell)
Morphology:
Prismatic to bladed generally rough to barrel-shaped crystals
Twinning:
Twinning is simple, by reflection, with twin boundaries across the length of the crystals.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.393 Å | (53) |
| 5.922 Å | (100) |
| 4.799 Å | (26) |
| 3.173 Å | (44) |
| 2.983 Å | (14) |
| 2.787 Å | (35) |
| 2.413 Å | (14) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites |
Type Occurrence of Footemineite
General Appearance of Type Material:
Prismatic to bladed generally rough to barrel-shaped crystals up to about 1.5 mm long and 1 mm in diameter
Place of Conservation of Type Material:
Museu de Geociências, Instituto de Geociências, Universidade
de São Paulo, Rua do Lago, 562, 05508-080, São Paulo, SP, Brazil
de São Paulo, Rua do Lago, 562, 05508-080, São Paulo, SP, Brazil
Geological Setting of Type Material:
Quartz-microcline-spodumene pegmatite
Associated Minerals at Type Locality:
Synonyms of Footemineite
Other Language Names for Footemineite
Dutch:Footemineiet
German:Footemineit
Relationship of Footemineite to other Species
Member of:
Other Members of Roscherite Group:
| Atencioite | Ca2Fe2+3Mg2Be4(PO4)6(OH)4 · 6H2O | Tric. 1 : P1 |
| Greifensteinite | Ca2Fe2+5Be4(PO4)6(OH)4 · 6H2O | Mon. 2/m : B2/b |
| Guimarãesite | Ca2Be4Zn5(PO4)6(OH)4 · 6H2O | Mon. 2/m : B2/b |
| Okruschite | Ca2Mn2+5Be4(AsO4)6(OH)4 · 6H2O | Mon. 2/m : B2/b |
| Roscherite | Ca2Mn2+5Be4(PO4)6(OH)4 · 6H2O | Mon. 2/m : B2/m |
| Ruifrancoite | Ca2(◻,Mn)2(Fe3+,Mn,Mg)4Be4(PO4)6(OH)4(OH,H2O)2 · 4H2O | Mon. 2/m : B2/b |
| Zanazziite | Ca2Mg5Be4(PO4)6(OH)4 · 6H2O | Mon. 2/m : B2/b |
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 8.DA.05 | Bearsite | Be2(AsO4)(OH) · 4H2O |
| 8.DA.05 | Moraesite | Be2(PO4)(OH) · 4H2O |
| 8.DA.10 | Zanazziite | Ca2Mg5Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Atencioite | Ca2Fe2+3Mg2Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Guimarãesite | Ca2Be4Zn5(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Greifensteinite | Ca2Fe2+5Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Roscherite | Ca2Mn2+5Be4(PO4)6(OH)4 · 6H2O |
| 8.DA.10 | Ruifrancoite | Ca2(◻,Mn)2(Fe3+,Mn,Mg)4Be4(PO4)6(OH)4(OH,H2O)2 · 4H2O |
| 8.DA.10 | Okruschite | Ca2Mn2+5Be4(AsO4)6(OH)4 · 6H2O |
| 8.DA.15 | Uralolite | Ca2Be4(PO4)3(OH)3 · 5H2O |
| 8.DA.20 | Weinebeneite | CaBe3(PO4)2(OH)2 · 4H2O |
| 8.DA.25 | Tiptopite | K2(Na,Ca)2Li3Be6(PO4)6(OH)2 · H2O |
| 8.DA.40 | Spencerite | Zn4(PO4)2(OH)2 · 3H2O |
| 8.DA.45 | Glucine | CaBe4(PO4)2(OH)4 · 0.5H2O |
Fluorescence of Footemineite
None
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Footemineite
mindat.org URL:
https://www.mindat.org/min-30765.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Footemineite
Reference List:
Fanfani, L., Nunzi, A., Zanazzi, P. F., Zanzari, A. R. (1975) The crystal structure of Roscherite. TMPM Tschermaks Mineralogische und Petrographische Mitteilungen, 22 (3). 266-277 doi:10.1007/bf01087845
Rastsvetaeva, R. K., Chukanov, N. V., Verin, I. A., Atencio, D. (2007) The crystal structure of footemineite. Doklady Earth Sciences, 416 (1) 1053-1056 doi:10.1134/s1028334x07070161
Atencio, D., Matioli, P. A., Smith, J. B., Chukanov, N. V., Coutinho, J. M.V., Rastsvetaeva, R. K., Mockel, S. (2008) Footemineite, the Mn-analog of atencioite, from the Foote mine, Kings Mountain, Cleveland County, North Carolina, U.S.A., and its relationship with other roscherite-group minerals. American Mineralogist, 93 (1) 1-6 doi:10.2138/am.2008.2469
Localities for Footemineite
Showing 3 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Brazil | |
| Leavens et al. (1990) |
USA | |
| Jim McGlasson collection et al. (Dr. H. Yang ) |
| Atencio et al. (2008) |
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Foote Lithium Co. Mine, Kings Mountain, Cleveland County, North Carolina, USA